Personalising a mobile with the ringtone of a favourite tune has become hugely popular in Europe and Asia, and as a result a songwriters' agency has moved to start the licensing of such music jingles.

Harry Fox, a licensing agency to over 27,000 music publishers representing some 160,000 songwriters, has created a system for instant or "one-stop" electronic licensing for ringtone providers, after about 20 providers approached it to license its works.

Gary Churgin, chief executive director at the Harry Fox agency, said: "The publishers are ever vigilant about their copyrights, whether it's Napster or ring tones."

Industry experts have said that jingles, which are digitally delivered music files that play tunes for up to 30 seconds when there is an incoming call on mobiles, represent a potential multi-billion dollar industry.

In Japan, such revenues are worth around $300m.

Last year EMI Music sued ringtone provider Yourmobile.com. EMI claimed the company did not have proper licences to distribute its songs in the form of ringtones. The suit has since been settled.

YourMobile recently signed an agreement with several music publishers, which allows it to provide a catalogue of songs online. They range from Missy Elliot's 'Get Ur Freak On' to Sinatra's 'I've got you under my skin'.